1. Field
The present disclosure relates generally to spacecraft and, in particular, to launch vehicles. Still more particularly, the present disclosure relates to a method and apparatus for reducing and managing flames that occur during ignition of rocket engines.
2. Background
A spacecraft is used for a number of different purposes. These purposes include communications, earth observation, meteorology, navigation, planetary exploration, and other types of purposes. Spacecraft may be manned or unmanned. Spacecraft include, for example, a satellite, a space shuttle, and other suitable types of spacecraft.
Most spacecraft are unable to reach outer space with their own propulsion systems. Typically, a launch vehicle carries the spacecraft into space. The space vehicle is a payload for the launch vehicle.
A launch vehicle is a structure with a number of rocket engines and is designed to carry a payload. Launch vehicles may be reusable or expendable, depending on the particular design. Launch vehicles also may use a number of different types of propellants. The propellants may be solid or liquid. Commonly used liquid propellants for rocket engines include hydrogen and oxygen.
With rocket engines using these types of cryogenic liquid propellants, the components of the rocket engines are typically cooled before igniting the rocket engines. This type of cooling is also referred to as preconditioning. The preconditioning of a rocket engine may be performed by, for example, pumping the propellants in liquid form through the engines without igniting the propellants. After the rocket engines have been preconditioned, the rocket engines may be ignited to launch the spacecraft.
When liquid hydrogen is used as the propellant for these types of rocket engines, the liquid hydrogen turns into hydrogen gas during preconditioning. With the generation of hydrogen gas, the hydrogen gas is often collected prior to ignition of the rocket engines. The collection of gas is performed using a gas collection system in the launch vehicle and/or in the launch pad structure. This collection of the hydrogen gas reduces the possibility of gas accumulation, an undesired ignition, a large flame engulfing the launch vehicle, a deflagration, and/or a detonation of the gases.
These collection systems, however, increase the expense and weight of a launch vehicle. The increased cost is especially undesirable when a launch vehicle is an expendable launch vehicle.
Therefore, it would be advantageous to have a method and apparatus that takes into account the issues discussed above, as well as other possible issues.